It is known to deliver data to remote data-receiving devices using network connections such as for example an Internet (and in particular a World Wide Web) connection. Further, intermediaries such as Web-Cache intermediaries are known, which cache data between a server holding the data and a data-receiving device to which data will be delivered. Although the primary function of the Web Cache Intermediary is to cache data it can also prevent multiple requests for the same data being transmitted from the data-receiving device to the server.
Prevention of the transmission of multiple requests is particularly important in situations in which the server undergoes a state change following the receipt of the request for data from the data-receiving device i.e. the request for data causes the data held on the server to change. Such requests are not generally cached and include those those requests containing form data and the like. Examples of such a state change include the placing of an order on an online shopping site, etc., in which multiple orders can result if multiple requests are not blocked.
Further, the number of types of device and/or applications being used to make network connections is increasing. For example devices such as PDA's, PC's, web enabled televisions, mobile telephones, and the like are now being used to access information.
Indeed, it is known to use a plurality of devices in conjunction with one another to access information. That is an aggregations of access data-receiving applications that may be brought together to form a distributed user interface. For example, a PDA may be used in conjunction with a PC wherein the PDA is used much like a remote control to control the data sent to the PC, but the PC is used to display the information (for which it is much better suited because of its higher display capabilities).